Elevator suspension device



Feb. 21, 1939. F. HYMANS ELEVATOR SUSPENSION DEVICE Filed Oct. 5, 1938 INVENTOR ATTORNEY Patented Feb. 21, 1939 invention melatesttoi-itractiom elevators and especially to. the=connectionsofetheahoisting. tropes to. the elevator? car and: counterweight. z

In.- traction-- eleyatora a epluralityleof hoisting 1 ropes are -provided; --theseoropes being. connectedatwtheir endsttot-the icarcand counterweightrand... extending around the hoisting sheave-r-at-thetop.- of...the hoistway ..Itis desirable .-that.the load on h s in -tropes. at.-both :the. car. and -counter..-=

- We ht rbe een-rally:-.distribu.ted.v 1 However, due res.-

peciallyz-toithetconditionsof: t the. hoisting ,sheave L at -.--the.-.-grooves;-.- unequalz .creepage of the ropes takes place. .Thisaresultstin. increasinglygunequal.. distribution 0t thee-load "until: .a :point isreachedvv .1.

where slippage. ofw one--or. -more ofathe ropes 0c curs.- Thislcausesemore.rapidwweartof thesheave grooves-in which tthefslippage occurs, aggravating thersituation. Mechanic'abequalizers in the f ormmofwcleverst or. equivalent arrangements .-.-to-which H the ends of the.-hoisti-ngfcablesa-arehconnected have rbeen'iprovidedxom:both the car and counterweight to overcome this condition but they do not accomplish their intended purpose. Springs have also been employed, a spring being interposed in the connection of the end of each rope to the car and also to the counterweight. While not a true equalizer, the spring suspension has the advantage over the previously mentioned mechanical equalizers not only of simplicity but also that if one or more ropes break or become so weak as not to share the burden of the load, this portion of the load is equally distributed to the other ropes. In certain installations, especially of the high speed gearless type, the acceleration and retardation may be such as to cause yielding of the springs in starting and stopping, resulting in teetering.

It is the object of the invention to provide spring suspension for both the elevator car and counterweight in which any possibility of teetering is eliminated.

The invention involves the connection of the counterweight ends of certain ones of the ropes directly to the counterweight and the car ends of such ropes through springs to the car and. of the car ends of the other ropes directly to the car and the counterweight ends of such ropes through springs to the counterweight. With such arrangement teetering cannot take place during starting or stopping as any expansion or contraction of the springs at either the car or the counterweight is prevented by the ropes directly connected to these bodies.

Features and advantages of the invention will can-J01 is=-.rai.sed .-andilorver.edlby. meansi of l the v hoistingamotontl I. An. electromechanical brake l5 actaon. a .drumd S'Jbnltli. motor. shaft". to aid in stopping the...motor.fand to .holdlit .while at' rest. The .motor= dr1ves.-.the= .hoistin'g .sheaye l4 over. .whichhpass.-tlie...hoisting. ropes l2 and .I3 fortthecarillland counterweight 1811 These ropes lay= in grooves fdrmeddnthsheave surface, one

Io'n each .rope. SiiLropes. are. .illustrate'dfi. The

ropes .extendfddwnwardlififrom .each' side of the I hoistingesheave .to .theiicarrand "counterweight. On-ltIie-Jcarlside, vthe. endsTIZfl'iof the three alternate' ropes 12" are secured "directly to the car frame 2| while the ends 22 of the other three ropes l3 are connected to the car frame through springs 23, illustrated for convenience as tension springs. 0n the counterweight side, the other ends 24 of ropes [2 are connected through springs 25 to the counterweight while the other ends of ropes I3 are connected directly to the counterweight. 4

Details of a suitable arrangement for connecting the ends of the ropes is illustrated in Figure 2 Where the direct connection of one of the ropes l2 and the connection of one of the ropes I3 through a spring to the car frame is shown. The ends of hoisting ropes l2 and I3 are fastened to thimble rods 26 and 21 respectively. These rods extend through apertures 28 in plate 30 secured to the car frame. Lock nuts 3| are provided on the lower end of rod 26 directly beneath the plate, thus securing the rod directly to the car frame. On the lower end of rod 21, however, a compression spring 32 is provided between plate 30 and lock nuts 3|. The ends of the other ropes are connected in a similar manner as are the connections of the other ends of the ropes to the counterweight. The tension of the ropes may be adjusted by adjusting the length of the suspension springs on both car and counterweight. This is effected by adjusting the positions of the lock nuts on the ends of thimble rods 21.

With such arrangement, any teetering of the car or counterweight during starting or stopping is prevented. For example, in starting the elevator car in the up direction, should the acceleration be such as to tend to compress the suspension springs (Figure 2) on the car side which would result in teetering, such expansion is prevented by the solid connection of the other ropes to the car frame. Similarly, in stopping the car during its travel in the down direction, should the retardation be such as to tend to compress the suspension springs on the car side which would result in teetering, such compression is prevented by the solid connection of the other ropes to the car frame.

Although the invention has been described as applied to a single wrap gearless traction machine, it is to be understood that it is also applicable to other types of drive.

As many changes could be made in the above construction and many apparently widely difierent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In a traction elevator system in which a plurality of hoisting ropes extend from the elevator car to the counterweight over a sheave,

characterized in that certain of said ropes are resiliently connected to the car at one end and directly to the counterweight at the other end, and that the remainder of said ropes are resiliently connected to the counterweight at one end and directly to the car at the other end.

2. In a traction elevator system in which a plurality of hoisting ropes extend from the elevator car to the counterweight over a hoisting sheave, means connecting the car ends of said ropes to the car, said connecting means comprising resilient means interposed between the car ends of certain of said ropes and the car, the car ends of the remaining ropes being directly connected to the car, and means connecting the counterweight ends of said ropes to the counterweight, said last named connecting means comprising resilient means interposed between the counterweight ends of said remaining ropes and the counterweight, the counterweight ends of said certain ropes being directly connected to the counterweight.

3. In a traction elevator system in which a plurality of hoisting ropes extend from the elevator car to the counterweight over a hoisting sheave, means connecting the car ends of said ropes to the car, said connecting means comprising a plurality of springs, one for each of certain ones of said ropes, interposed between the car ends of the respective ropes for which they are provided and the car, the car ends of the remaining ropes being directly connected to the car, and means connecting the counterweight ends of said ropes to the counterweight, said last named connecting means comprising a plurality of additional springs, one for each of said remaining ropes, interposed between the counterweight ends of the respective ropes for which they are provided and the counterweight, the counterweight ends of said certain ropes being directly connected to the counterweight.

4. In a traction elevator system in which the elevator car and counterweight are suspended by a plurality of hoisting ropes passing over a hoisting sheave, means directly connecting the car ends of half of said ropes to the car and the counterweight ends of the other half of said ropes to the counterweight, a compression spring for each rope, means connecting the counterweight ends of the first mentioned half of said ropes to said counterweight through said springs for such ropes, and means connecting the car ends of the second mentioned half of said ropes to said car through said springs for such ropes.

FREDERICK HYMANS. 

